Many parts of the world do not have adequate rainfall during portions of the year to maintain healthy turf and landscaping. Therefore irrigation systems are used that comprise an electronic irrigation controller that automatically turns valves ON and OFF that supply water to sprinklers installed around an irrigation site.
Pop-up rotor-type sprinklers that have an internal water turbine and gear train reduction for rotating their nozzles have been developed and widely commercialized. A large rotor-type sprinkler commonly used on golf courses includes a diaphragm valve that is mounted adjacent a female threaded inlet in the lower end of the outer housing. This diaphragm valve is opened and closed by a solenoid actuated pilot valve to admit water under high pressure into the outer housing. This pressurized water drives the turbine before being ejected from a removable nozzle carried in a rotating turret at the top of the pop-up riser. The diaphragm valve controls the entry of water into the outer housing of the sprinkler from a pressurized supply pipe to which it is connected. In many cases during the life of a so-called “valve-in-head” sprinkler the diaphragm valve will fail, often due to debris damaging the diaphragm valve seat or clogging the small passages in the diaphragm valve. The thin flexible diaphragm may also wear out. It is then necessary to shut OFF the water supply and dig up the sprinkler so that the defective diaphragm valve components can be repaired, or the sprinkler can be replaced in its entirety. This is a relatively expensive, tedious and time consuming process. Excavation of the defective sprinkler can also cause considerable damage to the surrounding landscaping and prevent golf from being played in the area of the golf course where the repair is taking place.
U.S. Pat. No. 6,491,235 granted Dec. 10, 2002 to Scott et al., and assigned to Hunter Industries, Inc., discloses a top serviceable valve-in-head rotor-type sprinkler with a diaphragm valve module that can be removed and replaced as a single unit after removal of the riser. This eliminates any need to dig up and replace the entire sprinkler. In commercial valve-in-head sprinklers of this type that are manufactured by Hunter Industries, Inc., the solenoid, pilot valve and pressure regulator are mounted inside a valve actuator component assembly housing formed on the side of the sprinkler case and accessible from the top side of the sprinkler. A lid in the large circular ground support flange extending from the top of the case may be opened to gain access to the valve actuator components for service or repair. The solenoid may be manually twisted to close the pilot valve to shut OFF the diaphragm valve to permit nozzle replacement. If maintenance personnel need to repair or replace the diaphragm valve module or any of the valve actuator components, it is necessary to manually shut OFF the supply valve that controls the supply of water to the sprinkler and bleed residual pressurized water in the supply line by running that zone until the water has been exhausted through the sprinkler. In the case where it is only necessary to work on the valve actuator components, the process of shutting off the water source is tedious and time consuming.